Just a thought: watching a parent leave to have a cigarette outside or something, from a child's perspective, isn't hugely damaging. The kid can't understand addiction nor lung cancer (and so on), so the kid's perception of "smoking = bad" is mostly only on how the kid themself feels.

With a phone, the kid can fell ignored, unheard, unengaged with the addicted parent for hours at a time, every single day.

Maybe kids will grow up thinking "hey, I don't wanna be a phone zombie like my daddy was," or something.